The current invention is related to powering notification appliance circuits (NACs), and in particular to a system and method for providing boost voltage and load-sharing for a plurality of NACs.
Emergency systems, such as fire systems, often contain one or more NACs. These NACs provide power to several emergency notification devices such as, but not limited to, strobe lights and sirens. Each notification device has a specified working voltage and current. Regulations require these NACs to continuously provide a proper working voltage and current in order to ensure continuous, uninterrupted operation of the emergency notification devices. Therefore, a power source must supply enough power to the one or more NACs to provide a working voltage and current to each notification device, taking into account any voltage drops such as those caused by wiring impedances and power switches.
Traditionally, NACs have been powered through the use of a single power supply. The power supply often contains an AC power source that is converted from AC to DC power. If this power supply malfunctions, the NACs are powered entirely by a backup power source. The backup power source usually consists of a backup battery. Batteries can only operate at a given voltage for a limited amount of time before the voltage of the battery drops. Once the voltage of the battery falls below the required working voltage of the NAC, the notification devices will fail to function as specified.